According to the video, changes in temperature and ocean depth
recorded by a tracking device that washed ashore after being
attached to the shark seemed to indicate that the tag had been
inside the stomach of another animal.

Internet speculation quickly spread, with many assuming that the
entire shark was consumed by a much larger shark. Some even
wondered if the shark had been devoured by a legendary creature
known as Megalodon, a 64-foot shark that went extinct
millions of years ago.

ButCSIRO,
the Australian science
agency leading the effort
to tag and track white sharks, set the story straightin
a blog post on Wednesday.

In late 2003,
scientists attached a tagdesigned to collect data
on swim depth, water temperature, and light
levels to the 9-foot
shark, Kirsten Lea from CSIRO
explained. The tag surfaced two weeks before
it was programmed to detach from the creature.

Over a three-week period the tag recorded temperature "consistent
with that of the core body temperature of a white shark but too
low for something like a killer whale," Lea wrote. Many batted
around the theory that the shark was eaten by a killer whale.

"All evidence suggests that the tag had been eaten by
another white shark," Lea said. "We concluded that this
was the most likely explanation – one shark bit off a little more
than he could chew and ended up swallowing the tag." She added:
"We never concluded that the 3m shark was consumed by another
much larger shark."

Lea also pointed out that shark-on-shark attacks are not
uncommon. "We have seen white sharks biting each other before,
sometimes removing pieces of tissue in the process."

David Shiffman, a marine biologist studying sharks at the
University of Miami, agrees with this view. "We don't know for
sure what happened in this case," he said in an email, "but large
sharks eat smaller sharks all the time."